PX 125 pinking - Pls help!!

[stonerosesmod]

Hi all, ive got a px 125 disc that has a new 150 top end fitted and a P2 carb.Ive ran her in for 250 miles at up to 40 mph with no probs,but now im trying to run at 45mph for another 250 miles.Trouble is,when you accellerate from 40 to 45,it pinks really heavily when you hold it there.Ive gone from a BP7ES plug to a colder BP8ES and the main jet is a 108 which leaves the plug a dark browny black colour.
The timing was retarded approx 1 degree when the kit was put on but can retarding it slightly more help cure the pinking?
Ive got a strobe light to check but does anyone know which marks i have to match up to be correct?

[stonerosesmod]

Just checked the marks with a strobe light,and the mark on the flywheel lights up around half way betweeb the two marks on the fan casing .Does that give any clues?
Ps,the marks were checked when the engine was revving a little.